The present invention relates to novel heptaene antibiotics, processes for their preparation and their use.
A large number of heptaene antibiotics has already been described. Heptaene antibiotics are macrocyclic lactones comprising as characteristic feature 7 double bonds conjugated together. They are natural substances which are obtained from microbes and are used as antimycotics, as antitrichomonal agents or as agents for binding steroids (cholesterol). However, some of them are very toxic compounds which, for this reason, are not used systemically (injected), except for the commercial product amphotericin B (The Merck Index, eleventh edition, 1989, page 93), the prototype of polyene antibiotics. Because of the increase in fungal diseases, there continues to be a great need for novel antifungal antibiotics which are either more effective or better tolerated than known polyene antibiotics.
It has now been found, surprisingly, that Streptomyces spec. HAG 3874, DSM 11007, is able to produce novel, highly active heptaene antibiotics which not only are very effective but in some cases are also well tolerated.